Influence of pruning and the climatic conditions on acorn production in holm oak (Quercus ilex L.) dehesas in SW Spain

摘要: Acorn production by Quercus ilex L. ssp. ballota (Desf.) Samp. in SW Spain was assessed, and variations between years the influence of pruning on it were examined. To this end, an experimental study conducted at two different sites (Calanas San Bartolome, province Huelva) where trees subjected to traditional (light, moderate or heavy) also a new (crown-regeneration) method. yield quantified over period 5 Calanas plot 4 Bartolome plot, found average 95.61 ± 0.76 g DM/m2, which is equivalent 6.5 0.05 kg DM/tree; however, figures varied markedly depending particular climatic conditions. The acorn correlated with water potential mid summer (end July); annual, spring autumn rainfall; actual evapotranspiration for from September (previous year) August. No significant differences intensities detected; fact, there only hints that heavy might result decreased yields. method used, crown-regeneration, seems promising view increasing yield; should be tested larger sample sizes before any final conclusions can drawn respect. Based results, present health status holm oaks southwestern (a sustained decline) low value firewood — used very important source income few decades ago -, authors recommend reducing frequency intensity dehesas area.